Reinforcement sensitivity theory (RST) proposes three brain-behavioral systems that underlie individual differences in sensitivity to
reward,
punishment
Punishment, commonly, is the imposition of an undesirable or unpleasant outcome upon an individual or group, meted out by an authority—in contexts ranging from child discipline to criminal law—as a deterrent to a particular action or beh ...
, and
motivation
Motivation is an mental state, internal state that propels individuals to engage in goal-directed behavior. It is often understood as a force that explains why people or animals initiate, continue, or terminate a certain behavior at a particul ...
. While not originally defined as a
theory of personality, the RST has been used to study and predict
anxiety
Anxiety is an emotion characterised by an unpleasant state of inner wikt:turmoil, turmoil and includes feelings of dread over Anticipation, anticipated events. Anxiety is different from fear in that fear is defined as the emotional response ...
,
impulsivity
In psychology, impulsivity (or impulsiveness) is a tendency to act on a whim, displaying behavior characterized by little or no forethought, reflection, or consideration of the consequences. Impulsive actions are typically "poorly conceived, pre ...
, and
extraversion
Extraversion and introversion are a central trait dimension in human personality theory. The terms were introduced into psychology by Carl Jung, though both the popular understanding and current psychological usage are not the same as Jung's ...
.
The theory evolved from
Gray's biopsychological theory of personality to incorporate findings from a number of areas in
psychology
Psychology is the scientific study of mind and behavior. Its subject matter includes the behavior of humans and nonhumans, both consciousness, conscious and Unconscious mind, unconscious phenomena, and mental processes such as thoughts, feel ...
and
neuroscience
Neuroscience is the scientific study of the nervous system (the brain, spinal cord, and peripheral nervous system), its functions, and its disorders. It is a multidisciplinary science that combines physiology, anatomy, molecular biology, ...
, culminating in a major revision in 2000. The revised theory distinguishes between fear and anxiety and proposes functionally related subsystems. Measures of RST have not been widely adapted to reflect the revised theory due to disagreement over related versus independent subsystems.
Despite this controversy, RST informed the study of
anxiety disorder
Anxiety disorders are a group of mental disorders characterized by significant and uncontrollable feelings of anxiety and fear such that a person's social, occupational, and personal functions are significantly impaired. Anxiety may cause phys ...
s in clinical settings and continues to be used today to study and predict
work performance
Job performance assesses whether a person performs a job (role), job well. Job performance, studied academically as part of industrial and organizational psychology, also forms a part of human resources management. Performance is an important crite ...
.
RST, built upon Gray's behavioral inhibition system (BIS) and behavioral activation system (BAS) understanding, also may help to suggest predispositions to and predict alcohol and drug abuse. RST, a continuously evolving paradigm, is the subject of multiple areas of contemporary psychological enquiry.
Origins and evolution of the theory
Gray's biopsychological theory of personality was informed by his earlier studies with Mowrer on
reward,
punishment
Punishment, commonly, is the imposition of an undesirable or unpleasant outcome upon an individual or group, meted out by an authority—in contexts ranging from child discipline to criminal law—as a deterrent to a particular action or beh ...
, and
motivation
Motivation is an mental state, internal state that propels individuals to engage in goal-directed behavior. It is often understood as a force that explains why people or animals initiate, continue, or terminate a certain behavior at a particul ...
and
Hans Eysenck
Hans Jürgen Eysenck ( ; 4 March 1916 – 4 September 1997) was a German-born British psychologist. He is best remembered for his work on intelligence and personality psychology, personality, although he worked on other issues in psychology. At t ...
's study of the biology of personality traits.
Eysenck linked
Extraversion
Extraversion and introversion are a central trait dimension in human personality theory. The terms were introduced into psychology by Carl Jung, though both the popular understanding and current psychological usage are not the same as Jung's ...
to activation of the
ascending reticular activating system, an area of the brain which regulates sleep and arousal transitions.
Eysenck's two original personality factors,
Neuroticism
Neuroticism is a personality trait associated with negative emotions. It is one of the Big Five traits. Individuals with high scores on neuroticism are more likely than average to experience such feelings as anxiety, worry, fear, anger, shame ...
and
Extraversion
Extraversion and introversion are a central trait dimension in human personality theory. The terms were introduced into psychology by Carl Jung, though both the popular understanding and current psychological usage are not the same as Jung's ...
, were derived from the same lexical paradigm used by other researchers (e.g.,
Gordon Allport
Gordon William Allport (November 11, 1897 – October 9, 1967) was an American psychologist. Allport was one of the first psychologists to focus on the study of the personality, and is often referred to as one of the founding figures of personali ...
,
Raymond Cattell
Raymond Bernard Cattell (20 March 1905 – 2 February 1998) was a British-American psychologist, known for his psychometric research into intrapersonal psychological structure.Gillis, J. (2014). ''Psychology's Secret Genius: The Lives and Works ...
) to delineate the structure of personality. Eysenck's Extraversion-Arousal Hypothesis states that under low stimulation conditions, introverts (defined as low in Extraversion) will be more highly aroused than extraverts; however, under high stimulation, introverts may become over-aroused, which will feedback within the ascending reticular activating system and result in ''decreases'' in arousal. In contrast, extraverts tend to show greater increases in arousal under high stimulation.
Eysenck also studied the relationship between
neuroticism
Neuroticism is a personality trait associated with negative emotions. It is one of the Big Five traits. Individuals with high scores on neuroticism are more likely than average to experience such feelings as anxiety, worry, fear, anger, shame ...
and activation of the
limbic system
The limbic system, also known as the paleomammalian cortex, is a set of brain structures located on both sides of the thalamus, immediately beneath the medial temporal lobe of the cerebrum primarily in the forebrain.Schacter, Daniel L. 2012. ''P ...
using classical emotional conditioning models. His theory focused more on
anxiety
Anxiety is an emotion characterised by an unpleasant state of inner wikt:turmoil, turmoil and includes feelings of dread over Anticipation, anticipated events. Anxiety is different from fear in that fear is defined as the emotional response ...
as a disorder than a personality trait.
Eysenck's theory predicts that introverts are more likely to develop anxiety disorders because they show higher neuroticism and stronger emotional conditioning responses under high arousal. His theory was criticized because introverts often show the opposite pattern, weaker classical conditioning under high arousal, and some supporting data confounded personality traits with time of day.
Gray's biopsychological theory: behavioral activation and inhibition systems
Unlike Eysenck,
Gray
Grey (more frequent in British English) or gray (more frequent in American English) is an intermediate color between black and white. It is a neutral or achromatic color, meaning that it has no chroma. It is the color of a cloud-covered s ...
believed that personality traits and disorders could not be explained by classical conditioning alone. Gray proposed the Biopsychological Theory of personality in 1970 based on extensive animal research.
[Larsen, R. J., & Buss, D. M. (2009). ''Personality Psychology: Domains of Knowledge about Human Nature.'' New York, NY: McGraw-Hill.] His theory emphasized the relationship between personality and sensitivity to reinforcement (i.e.
reward and
punishment
Punishment, commonly, is the imposition of an undesirable or unpleasant outcome upon an individual or group, meted out by an authority—in contexts ranging from child discipline to criminal law—as a deterrent to a particular action or beh ...
). Eysenck's theory emphasized Extraversion, Neuroticism, and arousal, while Gray's theory emphasized Impulsivity, Anxiety, approach motivation, and avoidance motivation.
In his original theory, Gray proposed two new dimensions to Eysenck's theory - anxiety and impulsivity.
Gray's anxiety, or BIS, correlates with Eysenck's neuroticism.
Gray's impulsivity, or BAS, correlates with Eysenck's extraversion.
Even though Gray's original theory was modified later by Gray himself, the original theory still made some contributions to the study of biological systems and their role in personality.
The largest of these contributions was that the biological central nervous system can be linked to a psychological reward system, composed of approach and inhibition systems.
Gray's model of personality was based on three hypothesized brain systems:
Behavioral activation system (BAS)
*The BAS includes brain regions involved in regulating arousal:
cerebral cortex
The cerebral cortex, also known as the cerebral mantle, is the outer layer of neural tissue of the cerebrum of the brain in humans and other mammals. It is the largest site of Neuron, neural integration in the central nervous system, and plays ...
,
thalamus
The thalamus (: thalami; from Greek language, Greek Wikt:θάλαμος, θάλαμος, "chamber") is a large mass of gray matter on the lateral wall of the third ventricle forming the wikt:dorsal, dorsal part of the diencephalon (a division of ...
, and
striatum
The striatum (: striata) or corpus striatum is a cluster of interconnected nuclei that make up the largest structure of the subcortical basal ganglia. The striatum is a critical component of the motor and reward systems; receives glutamat ...
. The system is responsive to conditioned and unconditioned reward cues. BAS regulates approach behaviors and is referred to as the reward system.
It has also been called the "go" system because it motivates actions that lead to rewards.
In general, individuals with a more active BAS tend to be more impulsive and may have difficulty inhibiting their behavior when approaching a goal.
[Gray, J. A. (1991). The neurophysiology of temperament. In J. Strelau & A. Angleitner (Eds.), ''Explorations in temperament: International perspectives on theory and measurement'' (pp. 105-128). New York, NY: Plenum.] Furthermore, BAS is related to stimuli associated with the presence of reward and/or the cease of punishment, also understood as positive reinforcement.
Behavioral inhibition system (BIS)
*The BIS also includes brain regions involved in regulating arousal:
the brain stem, and neocortical projections to the
frontal lobe
The frontal lobe is the largest of the four major lobes of the brain in mammals, and is located at the front of each cerebral hemisphere (in front of the parietal lobe and the temporal lobe). It is parted from the parietal lobe by a Sulcus (neur ...
. BIS is responsive to punishment, novelty, uncertainty, and non-rewarding stimuli. BIS regulates avoidance behaviors and is often referred to as the punishment system. It has also been called the "stop" because it encourages inhibition of behaviors.
Individuals with more active BIS may be vulnerable to negative emotions, including frustration, anxiety, fear, and sadness.
Furthermore, BIS is related to stimuli associated with the presence of punishment and/or the cease of reward, also understood as negative reinforcement.
Fight/flight system (FFS)
*The FFS encourages extreme reactions in response to threats.
These include reactions of rage, panic, and fight or flight, and is sensitive to unconditioned aversive stimuli. FFS is often referred to as the threat system.
A common misunderstanding can be that FFS is a measure of one's reaction to lean more towards fighting or to lean more towards fleeing in response to perceived threats;
however, FFS is a measure of one's intensity to respond with either fight or flight behavior, as opposed to reacting not so acutely to perceived threats.
Individuals with more sensitive FFS are quicker to fight or flee in dangerous situations.
According to Gray, personality traits are associated with individual differences in the strengths of BAS (approach motivation) and BIS (avoidance motivation) systems. As it is defined for the remainder of the article, higher BAS/BIS refers to greater activation of that system.
Measures
High BAS is generally associated with high extraversion, low neuroticism, and trait impulsivity, while high BIS is associated with low extraversion, high neuroticism, and trait anxiety. In addition to predicting
trait standings, high BAS is associated with higher ''positive'' affect in response to reward, while high BIS is associated with higher ''negative'' affect in response to punishment.
Studies in Gray's laboratory supported his prediction that extraverts, higher in BAS and lower in BIS than introverts, are more sensitive to rewards, experience higher levels of positive affect, and learn faster under rewarding conditions.
The most widely used measures of the approach (BAS) and avoidance (BIS) systems are the BIS/BAS scales developed by Carver and White in 1994.
The Generalized Reward and Punishment Expectancies Scales (GRAPES) were also used to operationalize BIS and BAS.
Both self-report measures (listed above) and behavioral measures (such as affective modulation of the eyeblink startle response) have been used to test predictions and provide mixed support for Gray's theory.
Critique
These measures were constructed under the assumption that BIS, BAS and associated traits Anxiety and Impulsivity are independent.
In contrast, Gray first described BIS and BAS as opposing systems with bidirectional inhibitory links in animal models.
Thus, empirical results that claimed to falsify the theory may have relied on faulty predictions for independent, non-interacting systems. Gray's theory was also criticized because the boundary between FFS (threat response system) and BIS (punishment system) was difficult to define empirically, akin to differentiating between fear and anxiety.
Matthews and Gilliland proposed separate cognitive systems underlying fear and anxiety and emphasized the need to study these systems outside of animal models.
These critiques led to a major revision and renaming of the theory in 2000.
The Reinforcement Sensitivity Theory (RST) redefined the three systems underlying anxiety, impulsivity, motivation, and reinforcement learning.
Reinforcement sensitivity theory
Reinforcement sensitivity theory is one of the major biological models of individual differences in emotion, motivation, and learning. The theory distinguishes between fear and anxiety, and links reinforcement processes to personality.
Behavioral activation system (BAS)
*Proposed to facilitate reactions to all appetitive/rewarding stimuli and regulates approach behavior.
Behavioral inhibition system (BIS)
*Proposed to mediate conflict both within and between FFFS and BAS: FFFS (avoidance) and BAS (approach) (or BAS-BAS, FFFS-FFFS). These conflicts underlie anxiety.
Fight-flight-freeze system (FFFS)
*Proposed to mediate reactions to all aversive/ punishing stimuli (conditioned and unconditioned), regulates avoidance behavior, and underlies
fear
Fear is an unpleasant emotion that arises in response to perception, perceived dangers or threats. Fear causes physiological and psychological changes. It may produce behavioral reactions such as mounting an aggressive response or fleeing the ...
.
Improved measures
The fight-flight-freeze system (FFFS) was expanded to include all aversive/punishment stimuli, conditioned and unconditioned. Similarly, the Behavioral Activation System (BAS) was expanded to include all appetitive/reward stimuli.
The Behavioral Inhibition System (BIS) was defined as a conflict system activated whenever both BAS and FFFS are activated together or multiple inputs compete within the systems, thereby producing anxiety.
If the systems are assumed to be functionally related, the effect of a given stimulus is dependent upon the strength of that stimulus, reactivity in the activated system, and strength of the competing system.
Thus, for a reward, the behavior output from BAS is dependent on the strength of the reward, activation of the BAS, and inhibition strength of BIS. For example, if a reward outweighs a threat, the BIS should excite the BAS and inhibit the FFFS, which will likely result in approach behavior.
The new RST distinguishes the subsystems underlying anxiety and fear. The FFFS is associated with fear and the BIS is associated with anxiety. This distinction is still debated, especially in clinical settings wherein BIS scores are sensitive to fear/panic-reducing, not anxiety-reducing treatments.
Furthermore, the possibility of anxiety's triggering panic and vice versa supports a model of the BIS and the FFFS in which the two are not causally independent. Conflicting results regarding the relationship between fear and anxiety may reflect measures which were not updated to reflect the functionally dependent systems of the new RST.
A review by Perkins and Corr (2006) found that the BIS as measured in Carver, 1994 scales
and similar constructs tap into the FFFS (which fear responses) and not the true BIS (which underlies anxiety). These definitions were not updated to reflect the revised RST model.
D.C. Blanchard and colleagues (2001) created vignettes with response options that modeled rodent reactions to anxiety (the BIS, used ambiguous/partially threatening stimuli) and fear (the FFFS, used pure threat situations) to study these constructs in humans.
These behavioroid scales ask: "What would you do if (insert scenario inducing fear or anxiety)?" Response options accurately reflect the revised RST, but have not been widely tested or applied.
Separable and joint subsystems hypotheses
The revised RST reflects functional dependence of the systems; however, there are two competing hypotheses developed for testing RST predictions. The separable systems hypothesis (SSH) is defined by two independent systems, reward and punishment.
Independence implies that reactivity to rewards should be approximately equal across all levels of punishment, and reactivity to punishment should be equal across all levels of reward. Thus, rewarding stimuli may activate the BAS, without exerting effects on the BIS or the FFFS.
The SSH is proposed to operate in extreme circumstances, within individuals with highly reactive systems and/or experimental conditions that only present rewarding or punishing stimuli.
The separable subsystems hypothesis has been applied successfully to study reinforcement learning and motivation in clinical populations.
Alternatively, the joint subsystems hypothesis (JSH), in accordance with Gray's original animal models and the revised RST, states that reward and punishment exert combined effects in the BAS and the FFFS, while the BIS resolves conflict within and between the systems. The reward and punishment systems are defined as dependent, such that reward activation (the BAS) both increases responses to appetitive stimuli and decreases responses to aversive stimuli. The joint subsystems hypothesis is most applicable in real-world contexts that contain mixed stimuli: strong, weak, punishment, and reward.
In a recent review on RST measurement, authors distinguished between dependent system inputs and dependent behavioral outputs.
The BAS, FFFS, and BIS are dependent systems, and current research attempts to define under what task situations and to what degree they interact. A rewarding stimulus may activate all three systems to some extent such that high scores on a BAS-related behavioral trait, for example, may include high BAS, low FFFS, and low BIS activations.
Corr and colleagues tested separate and joint subsystems predictions against each other.
Their results support the joint subsystems hypothesis: high anxiety individuals reacted more strongly to punishment cues, and this effect was stronger in jointly low impulsive, high anxiety individuals.
Pickering used
regression and
neural network models to show that patterns of inputs from the BAS and the BIS/FFFS generate a large range of outcomes that support the JSH (all three system activations were needed to determine best fit for behavioral output).
There is now pharmacological evidence to support dependence of these systems, notably
serotonergic (5-HT) modulation of the
dopamine pathway.
As mentioned previously, these complex, dependent systems are not reflected in questionnaires, such as Carver's BIS/BAS,
that are oftentimes used to test RST predictions. A variety of disparate experimental findings, originally viewed as inconsistent with Gray's Biopsychological theory, are more consistent with RST joint systems hypothesis.
Renaming impulsivity
Smillie, Pickering, and Jackson (2006) advocated for renaming trait Impulsivity, which is associated with BAS in the revised RST, Extraversion.
Empirical tests find that Extraversion is a better predictor than Impulsivity of reward learning.
Some components of the BAS and reward learning are better explained by association with Extraversion, especially high positive affect, while the cortical arousal loop originally proposed to underlie BAS in Gray's theory is still tied most closely with Impulsivity.
Regardless of the trait label, the authors point out that the RST did not develop as a theory to explain the personality constructs, Anxiety and Impulsivity.
Rather, the RST predicts associations between reinforcement sensitivity, motivation, and behavior.
Applications
Workplace performance
Carver and White's 1994 BIS/BAS scales
were used to support the finding that employees high in BIS (avoidance motivation) show lower
work performance
Job performance assesses whether a person performs a job (role), job well. Job performance, studied academically as part of industrial and organizational psychology, also forms a part of human resources management. Performance is an important crite ...
and engagement, while employees high in BAS (approach motivation) show higher performance in rewarding situations only.
These measures are not based on the revised RST, and may confound fear and anxiety. Alternatively, the Jackson 5 has recently been validated as a measure of the revised RST and shows convergent validity with measures of fear and anxiety.
The proposed fear (FFFS) subscale is associated with avoidance behaviors (example item: 'If approached by a suspicious stranger, I run away') while the anxiety (BIS) subscale includes social situations wherein reward and punishment stimuli result in conflict between approach and avoidance motivations (example item: 'I prefer to work on projects where I can prove my abilities to others'). Clark and Loxton (2011) used the Jackson 5 to investigate mediators between fear, psychological acceptance, and work engagement.
Self-reported fear, not anxiety, best predicted psychological acceptance, and lower work performance in turn.
Thus, current research aims to apply measures based on the revised RST to more accurately clarify relations between fear, anxiety, and
job performance
Job performance assesses whether a person performs a job well. Job performance, studied academically as part of industrial and organizational psychology, also forms a part of human resources management. Performance is an important criterion for o ...
.
Clinical research
The BIS and BAS sensitivities are associated with individual differences in positive and negative affect.
This association has been largely explored in clinical populations exhibiting extreme scores on BIS/BAS measures. In their 2009 review, Bijttebier and colleagues summarized studies showing that high BIS sensitivity is present in individuals with anxiety, depression, and
anorexia nervosa
Anorexia nervosa (AN), often referred to simply as anorexia, is an eating disorder characterized by Calorie restriction, food restriction, body image disturbance, fear of gaining weight, and an overpowering desire to be thin.
Individuals wit ...
, whereas low BIS sensitivity is associated with
psychopathy
Psychopathy, or psychopathic personality, is a personality construct characterized by impaired empathy and remorse, along with bold, disinhibited, and egocentric traits. These traits are often masked by superficial charm and immunity ...
.
Extremely high BAS sensitivity is characteristic of individuals with
bipolar disorder
Bipolar disorder (BD), previously known as manic depression, is a mental disorder characterized by periods of Depression (mood), depression and periods of abnormally elevated Mood (psychology), mood that each last from days to weeks, and in ...
,
ADHD
Attention deficit hyperactivity disorder (ADHD) is a neurodevelopmental disorder characterised by symptoms of inattention, hyperactivity, impulsivity, and emotional dysregulation that are excessive and pervasive, impairing in multiple ...
, and
bulimia
Bulimia nervosa, also known simply as bulimia, is an eating disorder characterized by binge eating (eating large quantities of food in a short period of time, often feeling out of control) followed by compensatory behaviors, such as self-induc ...
, while extremely low BAS often characterizes individuals with
anhedonic depression. BIS and BAS may differentiate, as illustrated above, between sub-types of
eating disorders
An eating disorder is a mental disorder defined by abnormal eating behaviors that adversely affect a person's health, physical or mental health, mental health. These behaviors may include eating too much food or too little food. Types of eatin ...
and
depression.
These findings are correlational, and causal mechanisms were not directly tested. Researchers in fields ranging from cognitive science to self-regulation and attention are using the RST to investigate causal mechanisms that underlie the relationship between personality traits and psychopathology.
A study by Masuyama et al. suggests that treatment interventions, which increase trait resilience, may be helpful in decreasing depressive symptoms.
High BIS was found to correlate directly with stronger depressive symptoms, while high BAS was found to correlate directly with low depressive symptoms.
This confirmed results from previous studies.
The study tested trait resilience as a mediator and found that trait resilience correlates negatively with depression.
Therefore, high BAS leads to high trait resilience, which in turn leads to lower depressive symptoms.
High BIS leads to decreased trait resilience, which in turn leads to increased depressive symptoms.
Some research shows that BIS and BAS levels may be useful in predicting onset of substance use disorders. Individuals with a stronger, more-sensitive BAS system correlated with early onset of substance use disorders.
Levels of BIS and BAS can be used to predict levels of substance use.
Individuals with low BIS levels combined with high BAS levels showed activation patterns similar to activation patterns of heavy substance users in past studies.
Individuals with high BIS levels and low BAS levels showed patterns of expectancy activation similar to those of light or non-users.
See also
*
Biological basis of personality
*
Extraversion and introversion
Extraversion and introversion are a central trait theory, trait dimension in human personality psychology, personality theory. The terms were introduced into psychology by Carl Jung, though both the popular understanding and current psychologic ...
*
Personality psychology
Personality psychology is a branch of psychology that examines personality and its variation among individuals. It aims to show how people are individually different due to psychological forces. Its areas of focus include:
* Describing what per ...
*
Reinforcement
In Behaviorism, behavioral psychology, reinforcement refers to consequences that increase the likelihood of an organism's future behavior, typically in the presence of a particular ''Antecedent (behavioral psychology), antecedent stimulus''. Fo ...
*
Trait theory
In psychology, trait theory (also called dispositional theory) is an approach to the study of human personality psychology, personality. Trait theorists are primarily interested in the measurement of ''traits'', which can be defined as habitual pa ...
References
{{Reflist, 2
External links
The BIS/BAS ScaleThe BIS/BAS scale with scoring instructions
Psychological theories